Searchers recovered the body of a Natrona County man on Wednesday afternoon after he apparently drowned during a fishing trip.

A preliminary investigation indicated Shane Fulmer, 41, died in an accidental drowning, Natrona County sheriff's Sgt. Mark Sellers said Thursday.

Authorities don't know what led to the drowning.

"There were no witnesses, so we don't know exactly why or how he entered into the river at this time," Sellers said.

Fulmer was last seen alive on Tuesday morning when he left to go fishing. His car was later found at the Bryan Stock Trail river access.

Investigators believe he was fishing from shore.

Fulmer was reported missing on Wednesday morning and the sheriff's office began a search of the river. A deputy and a Wyoming Game and Fish officer found Fulmer's body about a quarter mile downstream from where he had gone fishing, Sellers said.

Casper and Natrona County fire crews recovered the body.

The Natrona County Coroner's Office has begun its investigation of Fulmer's death but hasn't determined an official cause yet, said Chief Deputy Coroner Wayne Reynolds. That information could be available later today.

Anyone with information on the drowning is asked to contact the sheriff's office at (307) 235-9282.

Reach crime reporter Joshua Wolfson at (307) 266-0582 or at josh.wolfson@trib.com. Read his blog at tribtown.trib.com/JoshuaWolfson/blog.